Well shooting bridge



Jan. 21, 1941.

H. L. McLAUGHLlN 2,229,581

WELL SHOOTING BRIDGE Filed Oct. 15, 1937 2 Sheets-Sheet 1 HighL.McLaughIin INVENTOR.

ATTORNEY.

Jan. 21, .1941. L. MCLAUGHLIN 2,229,581

WELL SHOOTING BRIDGE Hugh L.McLau yl11in INVENTOR ATTORNEY.

Patented Jan. 21, 1941 UNITED. STATES.

PATENT OFFICE 13 Claims.

This invention relatesto animprovement in bridges used in connectionwiththeshooting of oil wells withnitroglycerin or other explosives.

Various kinds of bridges have been suggested heretofore, but in generalthey had to be positioned at the desired depth in the Welland held thereunder various conditions until the charge of nitroglycerin hadbeenintroduced anddetonated.

The primary object of, this inventionis to successfully overcome theseobjections byproviding a bridge that can be placed at any desired depthin. a well and secured thereagainst further downward movement.

Another object of this invention is to provide for the escape of gasfrom an obstruction in the well and at the same time holding in place acharge of nitroglycerin or other explosive until such time as theexplosive is setoif;

A preferred embodiment of this: invention is set forth in theaccompanying drawings, in which:

Fig. 1 is a side elevation of this improved bridge, partly in section;

Fig. 2 is a side elevation taken at right angles to Fig. 1;

Fig. 3 is a view similarto Fig. 1, engaging lugs in set position;

' Fig. 4 isa transverse section on the lne 4-4. of 30 I, looking in thedirection indicated by the arrows; and

Fig. 5 is a perspective view of the lug spring detached.

With more detailed reference to thedrawings,

a the numeral 6 represents the body of the tool which is formed offiatwebs turnedat right angles to each other, int-the shape of a crossin cross section and. having tapered upper and lower ends to facilitatetheinsertion into and removal from the well as shown in Figsl 1 and 2.The crossed shape of the body portion 6 causes it to obstruct the wellsuificiently to permit a container of nitroglycerin or other explosiveto be held firmly against downward movement. thereby and yet permit theescape ofgas from within the well, so that the bridge will notbe movedupward by gas pressure.

Wall engaging lugs 8 are mounted on opposite sides of the body 6, eachlug being U-shaped with its sides embracing an edge of the Web, andbeing pivctally secured, thereto by a pin l0. Triggers I2 extendupwardly within the U-shaped lugs 8 and bear thereagainst, being heldfirmly by a spring I4. coiled about each of the pins H), with one end ofeach spring bearing against the trigshowingthe ger f2 and the other endanchored to the Web. These springs 14 hold the triggers firmly in placeas long as the device is moving downwardly in the well.

The lower end of each trigger I2 has a curved wall-engaging surface it,adapted to slidably bear against the wall of the well, which isdesignated generally by the numeral [8, being pressed thereagainst by acoiled spring 25). The spring 29 is sleeved over a rod 22, pivoted at 23to the inner sideof the trigger I2, while the op posite end of the rod22 is slidably received in' a clevis 24, which in turn is pivoted by apin 26 to the web of thebody 6. The coiled spring 20 is interposedbetween the clevis 24 and the trigger l2, and the pivotal connection ofthe trigger with the body permits the former to move downward from theposition shown in Fig. 1 to'the position shown in Fig. 3, whereup thelugs fi dig into the wall of the well upon the body being-raised, as gshown in Fig. 3.

A pawl 30 is pivotally mounted on each trigger l2 with its pointdirected outwardly against the wallet the well l8, where it is urged bya spring 32. On the downward movement of the bridge, the pawls 30 do notengage the-wall of the well, but upon upward movement of thetooltherein, the points of the pawls 36' engage in the wall of the well andcause the triggers 2 to slidedownward irom their normal positions shownin Fig. 1 to the positionsshown in Fig. 3, the upperencls of thetriggers being separated'from the lugs 8 and permitting the springs M toact directlythereon. This causes the lugs 8' to be turned outwardlyagainst the wall of the well. and-upon downward movement of the bridgetherein, the lugs El will dig into the wall to the positions shown'inFig. 3. At this point, the maximum engagementef the lugsis afiorded,having their pointsin horizontal alignment with the pivot pins l9;

After the lugs have become; engaged with the wall of the well, the cableused in lowering the bridge into the well may be disconnected from eye34' attached to the upper end of body 6, as by any suitable trip means,and the bridge is allowedto remain in the l well.

After the tool has been placed at the desired depth in the well, upwardmovement of only a few inches is sufiicient to cause the lugs 8 toengage the side walls. Teeth 36 are provided on lugs 8 to grip the wallscreasing-or hard formations and provide a more secure engagement, wheretheir use is needed. Should it become necessary to remove the bridgebefore the well is shot it is only necessary. to recouple the cable withthe eye 34 and raise the tool upward as the lugs 8 will disengage theformation and permit easy removal of the bridge. The pawls 30 onlyengage into the formation deep enough to cause the triggers l2 to slidedownward. After the triggers l2 are moved downward out of engagementwith lugs 8 and springs M the upper ends will swing inward into recessesjust below lugs 8. This will cause pawls 30 to move inward sufficientlyto clear the walls of the well, should it be desired to remove thebridge without shooting the well.

A hole 38 is provided in the lower end of the bridge so that additionalweight may be attached if desired, as may be necessary when gas pressureis great.

After the bridge is located in the well in the correct position andbefore the nitroglycerin charge is placed thereon, a drilling tool orbail-er may be lowered until its weight tests the hold of the lugs onthe walls of the well.

Most of the parts of the bridge are preferably made of a material, suchas cast iron, that is readily broken up by the force of the explosionand does not remain in the well as an obstruction, the pieces beingblown into the formation.

The engaging lugs are shown on only two edges of the device, but it willbe readily appreciated that they can be placed on as many of the edgesas is deemed necessary or desirable.

It will be evident that the usual purpose of the bridge in shooting anoil well with nitroglycerin is to form an obstruction within the wellata point above the bottom, where an oil producing strata is located.After the bridge is set in place a container of nitroglycerin is loweredinto the well and allowed to come to rest upon the bridge. Thenitroglycerin is then detonated in the usual manner. The bridge holdsthe charge in place until it can be set off. 7

I claim: 7

1. In a well bridge, a body having a crosssection in the shape of across, lugs pivotally mounted on the sides of said body, trip meansarranged for engagement with said lugs and normally holding the lugsretracted, pawls so connected with the trip means as to permitfreedownward movement but to engage the wall of a well upon upward movementof the body relative thereto to release the trip means from the lugs,said lugs being arranged for engagement with the wall of the well afterbeing tripped but permitting upward movement of the body relativethereto, and resilient means tending to urge the trip means outwardagainst the wall of the Well.

' 2. A well shooting bridge comprising a body having lugs pivotallyconnected therewith, trip means for the respective lugs acting directlyon said lugs normally holding said lugs retracted, said trip means beingconstructed for release from the lugs upon tripping, said lugs beingconstructed for engagement upon downward movement of the bridge afterbeing tripped. and being disengageable upon upward movement of saidbridge, and pawls pivotally connected with. the trip means and arrangedto permit downward movement of the bridge and engaging walls of the wellupon upward movement of the bridge relative thereto.

pivotally connected with the body and bearing on the lugs normallyholding the lugs in set positions, said triggers being detachable fromthe lugs for releasing the same, and means for holding the triggers inretracted positions after disengagement from the lugs.

4. A well shooting bridge comprising a body having anchoring lugspivoted thereto, triggers pivotally connected with the body and bearingon -the lugs, said triggers having means for bearing against walls ofthe well, resilient means acting on the triggers, and pawls connectedwith the triggers in positions to-engage the walls of the well.

5. A well shooting bridge comprising a body constructed substantially inthe shape of a cross in cross-section, anchoring lugs pivoted to saidbody at different sides thereof, triggers pivotally andyieldablyconnected with the body and extending into operative connectionwith the lugs, said triggers having portions extending into positions toengage walls of the well, and pawls connected withthe triggers inpositions to engage the wallsof the well.

6. A well bridge comprising a body, and means for anchoring said body ina well to receive thereupon an explosive charge, said body beingconstructed in cross section in the shape of a cross with openpassageways therethrough from end to end when anchored in the wellproviding for the flow of fluid thereby from within the well.

'7. A well shooting bridge comprising a body,

' and means for anchoring the body in a well, said anchoring meansincluding a lug connected with the body for outward movement relativethereto, resilient means in position to bear against the lug to move thesame outward, means interposed between the lug and said resilient means,normally tending to prevent outward movement of the lug by the resilientmeans, and trip means connected with said interposed means forwithdrawing the same for outward movement of the lug by the resilientmeans.

8. A well shooting bridge comprising a body, and means for anchoring thebody in a well, said anchoring means including a lug connected with thebody for outward movement relative thereto, resilient means in positionto bear against the lug to move the same outward, means interposedbetween the lug and said resilient means,

normally tending to prevent outward movement of the lug by theresilientmeans, and wall engaging means connected with said interposed means forwithdrawing the same for outward movement of the lug by the resilientmeans.

9. A well shooting bridge comprising abody, and means for anchoring thebody in a well, said anchoring means including a lug connected with thebody for outward movement relative thereto, resilient means in positionto bear against the lug to move the same outward, and a trigger having awall engaging portion and a portion extending between the resilientmeans and the lug to prevent outward movement. of the lug by theresilient means.

10. A well shooting bridge comprising a body, and means for anchoringthe body in a well, said anchoring means including, a lug connected withthe body for outward movement relative thereto, resilient means inposition to bear against the lug to move the same outward, a triggerhaving a wall engaging portion and a portion extending between theresilient means and the lug to prevent outward movement of the lug bythe resilient means, and a pawl pivotally connected with the wallengaging portion of the trigger in position to engage the wall to holdthe trigger against movement relative thereto.

11. A well shooting bridge comprising a body, and means for anchoringthe body in a well, said anchoring means including a lug connected withthe body for outward movement relative thereto, resilient means inposition to bear against the lug to move the same outward,- and atrigger having a wall engaging shoe and an extended arm interposedbetween the resilient means and the lug to prevent outward movement ofthe lug by the resilient means, means pivotally supporting said triggeron the body, and resilient means bearing against the shoe tending tomove the same against the wall.

12. A well shooting bridge comprising a body, a plurality of lugsconnected with the body on different sides thereof, each of said lugsbeing U-shaped and embracing a portion of the body and pivoted thereto,resilient means arranged within each U-shaped lug in position to bearupwardly thereon, and a trigger for each lug having a portion interposedbetween the resilient means and said lug tending to prevent outwardmovement of the lug by said resilient means.

13. A well shooting bridge comprising a body, a plurality of lugsconnected with the body on different sides thereof, each of said lugsbeing U-shaped and embracing a portion of the body and pivoted thereto,resilient means arranged within each U-shaped lug in position to bearoutwardly thereon, a trigger for each lug having a portion interposedbetween the resilient means and said lug tending to prevent outwardmovement of the lug by said resilient means, said trigger having a wallengaging shoe, means supporting the trigger for movement relative to thebody, and a pawl pivotally connected with the trigger in position toengage the Wall of the well.

HUGH L. MCLAUGHLIN.

